Barbed wire of increased tear resistance

ABSTRACT

In the mounting of barbed wire as on fence posts it frequently happens that the wire is broken in the tensioning. This tensioning is generally done with a mechanical device. The difficulty is due to the fact that the wire has a very low extensibility prior to breaking. Methods of shaping the wire during manufacture are disclosed; by such shaping the extensibility is increased and the likelihood of breaking during the mounting process is decreased or eliminated.

United States Patent Volbach et al.

Feb. 8, 1972 'BARIBED WIRE OF INCREASED TEAR RESISTANCE Inventors: Heinz Volbach, Cologne, Germany; Oscar Julien Van Driessche, De Pinte, Belgium A l ed A. Arbed-Feltgn & Guilleaume Vereinigte Drahtwerke, Cologne-Muelheim, Germany Filed: Apr. 24, 1970 Appl. No.: 31,655

Assignee:

Foreign Application Priority Data Sept. 10, 1969 Germany ..P 19 45 730.8

US. Cl ..256/6 Int. Cl ..E04h 17/04 Field of Search ..256/29, 32, 34

References Cited UNITED STATES PATENTS McNeill ..256/6 Primary Examiner-Dennis L. Taylor Attorney-Michael S. Striker [57] ABSTRACT In the mounting of barbed wire as on fence posts it frequently happens that the wire is broken in the tensioning. This tensioning is generally done with a mechanical device. The difficulty is due to the fact that the wire has a very low extensibility prior to breaking. Methods of shaping the wire during manufacture are disclosed; by such shaping the extensibility is increased and the likelihood of breaking during the mounting process is decreased or eliminated.

4 Claims, 3 Drawing Figures BARBED WIRE OF INCREASED TEAR RESISTANCE BACKGROUND OF THE INVENTION In the standard procedures of mounting barbed wire a mechanical tightener is generally used. This tightener draws up the wire by a preselected amount which is such that the amount of sag between mounts is controlled. Since the extensibility of the wire used in the manufacture of barbed wire is low, there is not much margin for error in establishing the amount by which the wire is to be drawn up. As a result, it frequently happens that the wire is broken in the process of mounting.

Attempts have been made to get around this difficulty by a variety of means. One means has been to make a fundamentally stronger wire by using strips stamped from sheet which are then twisted together. In a second method, the wire is periodically given a reverse twist. Both of these methods have the disadvantage that the rate of production is substantially lower than that of conventional barbed wire, resulting in an increase in cost. It has therefore been desirable to discover a means of preparing barbed wire with great extensibility which does not involve any substantial increase in the equipment required and which can be produced at rates close to those at which standard barbed wire is made.

SUMMARY OF THE INVENTION It is an object of the invention to produce a barbed wire which will not break during the mounting process.

It is a further object of the invention to produce a barbed wire of greater extensibility than the present material.

It is another object of the invention to produce such a barbed wire without increase'in costs of machinery involved or decrease in rate of production.

We have found that if the barbed wire is periodically crimped or shaped into a waveform that the extensibility is greatly increased and the tendency to tear during mounting and pretensioning is greatly decreased. The wire takes a permanent set in crimping or waving as a result of which the apparent length of a given portion of wire is decreased. During pretensioning the crimps or waves tend to straighten out and the extensibility of the wire is therefore substantially increased and breakage of the wire is avoided.

The novel features which are considered as characteristic of the invention are set forth in particular in the appended claims. The invention itself, however, both as to its construction and its method of operation, together with additional objects and advantages thereof, will be best understood from the following description of specific embodiments when read in connection with the accompanying drawing.

BRIEF DESCRIPTION OF THE DRAWING FIG. 1 is a side view of a length of barbed, twisted wire showing a crimp therein;

FIG. 2 is again a length of barbed, twisted wire in which individual wires are crimped; and

FIG. 3 shows a length of barbed wire which is not pretwisted and in which the wires are both given a waveform.

DESCRIPTION OF THE PREFERRED EMBODIMENTS In the manufacture of ordinary barbed wire, multiple wires are generally used. These may be pretwisted and periodically, barbs are inserted between the wires. In FIG. I, such a barb or pair of barbs can be seen as reference numeral 3 inserted between the wires 1 and 2. The wires between the barbs lie in close contact with each other, and also lie along a straight line from one barb to the next. The wire from which barbed wire is made is of such a nature that it readily takes what is called a permanent set. Such a set can be imposed on the wire in the form of a crimp. FIG. 1 shows a preferred embodiment with a crimp 4. In this particular case, there is no crimp between the two sets of barbs shown; in general, crimps would be impressed on the wire periodically as the wire is twisted to ether. he equipment required for such a process IS nominal th in cost and in floor space consumed. In FIG. I, the crimps are impressed at the same location for both wires in the wire structure. Obviously for a stronger barbed wire, more than two strands might be used. However, these would all also be crimped at the same location.

FIG. 2 again shows a twisted two-strand barbed wire, but in this case wire I is crimped at position 5, whereas wire 2 is crimped at position 6 between the two barbs shown. For this to be effective, the wires 1 and 2 must be mounted slidably upon each other; otherwise wire 2 would be subjected to the entire stress at position 5, and wire I would take the entire stress at position 6. For maximum effectiveness with this arrangement, the number of crimps in wire I must equal the number of crimps in wire 2 and the size of the crimps must be essentially the same for both wires, when measured over a length of wire which is long compared to the distance between successive crimps. The arrangement can obviously be extended to three or more strands in a wire structure.

FIG. 3 shows an example in which the two strands of the wire comprising the barbed wire are not twisted together. In order to gain extensibility, the wires are bent into the form of a wave. This wave can be impressed periodically on the barbed wire as it is manufactured. Obviously, a wave could be impressed on the twisted wire strands as well. The frequency of the waves and the displacement of the waves from the straight line between successive barbs will depend on the desired increase in extensibility for the wire structure.

It is not usually necessary that the crimping should be spaced exactly as are the barbs. According to the required extensibility needed, the completed barbed wire can have crimps spaced between successive barbs, or more than one crimp between successive barbs, or crimps smaller in number than the number of barbs.

It will be understood that each of the elements described above, or two or more together, may also find a useful application in other types of constructions differing from the types described above.

While the invention has been illustrated and described as embodied in barbed wire of increased tear resistance, it is not intended to be limited to the details shown, since various modifications and structural changes may be made without departing in any way from the spirit of the present invention.

Without further analysis, the foregoing will so fully reveal the gist of the present invention that others can by applying current knowledge readily adapt it for various applications without omitting features that, from the standpoint of prior art, fairly constitute essential characteristics of the generic or specific aspects of this invention and, therefore, such adaptations should and are intended to be comprehended within the meaning and range of equivalence of the following claims.

What is claimed as new and desired to be protected by Letters Patent is set forth in the appended claims.

1. A barbed wire comprising two twisted wires and barbs secured to said twisted wires at spaced intervals, each of said twisted wires including wire portions laterally displaced from a straight line connecting consecutive barbs through a distance greater than the remainder of said twisted wires, the displaced portions of one wire being spaced in the direction of said twisted wires from the displaced portions of the other twisted wire.

2. A barbed wire as defined in claim 1, wherein the displaced wire portions on said two wires are respectively located on opposite sides of consecutive barbs.

3. A barbed wire as defined in claim 2, wherein the displaced wire portions on opposite sides of consecutive barbs are respectively displaced in opposite directions from said straight line.

4. A'barbed wire as defined in claim 2, wherein said displaced wire portions on opposite sides of consecutive barbs are substantially equally spaced from the respective barb. 

1. A barbed wire comprising two twisted wires and barbs secured to said twisted wires at spaced intervals, each of said twisted wires including wire portions laterally displaced from a straight line connecting consecutive barbs through a distance greater than the remainder of said twisted wires, the displaced portions of one wire being spaced in the direction of said twisted wires from the displaced portions of the other twisted wire.
 2. A barbed wire as defined in claim 1, wherein the displaced wire portions on said two wires are respectively located on opposite sides of consecutive barbs.
 3. A barbed wire as defined in claim 2, wherein the displaced wire portions on opposite sides of consecutive barbs are respectively displaced in opposite directions from said straight line.
 4. A barbed wire as defined in claim 2, wherein said displaced wire portions on opposite sides of consecutive barbs are substantially equally spaced from the respective barb. 